The present invention relates to a multicore fiber that is suitable for the case where a crosstalk between cores is decreased.
Presently, an optical fiber for use in optical fiber communication systems, which are generally popular, is in a structure in which one core is enclosed with a cladding, in which an optical signal is propagated through the inside of the core and information is transmitted.
In the optical fiber communication system in these years, a large number of from a few tens to a few hundreds of optical fibers are used, and the amount of information for transmission is dramatically increased. In order to decrease the number of optical fibers in such an optical fiber communication system, a multicore fiber is proposed in which a plurality of cores is enclosed with a cladding.
For example, a multicore fiber is proposed in Patent Document 1 below, in which a single core is disposed in the center of a cladding and six cores are disposed at positions to be the vertexes of a hexagon.
[Patent Document 1] JP-A-2011-193459